Re: NetBSD-current on amd64 with Dell PERC 4e/Di hangs under load

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

Christos Zoulas wrote:
>On Jan 28,  7:37pm, tih%hamartun.priv.no@localhost (Tom Ivar Helbekkmo) wrote:
>-- Subject: Re: NetBSD-current on amd64 with Dell PERC 4e/Di hangs under load
>
>| Christos Zoulas <christos%zoulas.com@localhost> writes:
>| 
>| > Can you boot with a single processor?  Let's try to simplify the
>| > workload.
>| 
>| Should have thought of that myself.  It's running with SMP disabled now
>| (as a boot option; I haven't done anything to the BIOS configuration),
>| and this is very interesting.  I've got all my regular software running,
>| plus a full system build with "-j 4", to make sure it's kept really
>| busy, and it's showing up hangs.
>| 
>| However: the hangs are short (5 to 10 seconds, typically, although I've
>| seen almost 20 a couple of times), and occur at varying intervals,
>| seemingly depending on how much disk access is going on: more often when
>| more is being written to disk.  Best of all, when it hangs, the system
>| seems totally unresponsive, neither answering ICMP ECHOs nor echoeing
>| keypresses on the console, but it *is* accessing the disks!  The disk
>| lamps flicker, indicating that it's writing stuff, and then, presumably
>| when it's gone through the outstanding writes, the machine continues to
>| run other tasks.  Here's a typical snapshot from the ping(1) I've got
>| running on a window on my workstation:

[snip]

>
>Excellent! This sounds like a very interesting problem... I am being
>pulled in every which direction right now, so I don't have much time
>to look into it, but I'll try to do so over the weekend (look at amr.c).

I see noticeable disk freezes on a system of mine which I had presumed
were down to wapbl(4) flushing the log to disk.

One difference for me is that the network still works fine, it is
running as a router with one bge(4) and one wm(4), the disk controller
is ixpide(4).